Reconciling Alternative Theories for the Safety of Owner–Operators

Motor carrier safety is an important concern of shippers, carriers, policy makers, consignees, insurance providers, and the motoring public. One aspect of carrier safety that has garnered substantial attention is whether carriers making greater use of owner–operators are more or less safe vis‐à‐vis carriers making greater use of employee drivers. Currently, conflicting theoretical predictions exist regarding the direction of this relationship. In this article, we offer a reconciliation of the alternative theoretical predictions by developing a coherent theory that merges sociological rational choice theory and theory regarding motor carrier safety. We subject our theory to empirical testing by fitting a series of seemingly unrelated regression models to a vector of safety measures tracked as part of the Federal Motor Carrier Safety Administration's Compliance, Safety, and Accountability program. Our results are consistent with our proposed theory of owner—operator safety and provide meaningful theoretical and managerial implications and directions for future research.     

基于应变数线性变换的约束广义G-M估计

考虑线性变换对约束线性模型回归系数的影响问题，证明了观测数据的线性变换对于约束模型的影响可以通过一个可用两步约束最小二乘法解决的约束回归问题进行了分析，得到了回归系数的约束可估函数的约束最佳线尾无偏估计不受变换影响的充要条件。     

电动搬运车辆斩波器的应用分析

介绍以蓄电池和串励直流电动机为动力的电动搬动车辆用斩波器的种类，型号，参数，电路原理和应用情况。     

基于分组的异方差检验和两阶段估计

本文提出了一种基于分组的异方差检验法，并给出了存在异方差时的两阶段估计。     

Two–step sequential sampling

Choosing the sample size in advance is a familiar problem: often, additional observations appear to be desirable. The final sample size then becomes a random variable, which has rather serious consequences.
Two such sample extension situations will be considered here. In the first situation, the observed sample variance determines whether or not to double the original sample size. In the second situation, the variances observed in two independent samples are compared; their ratio determines the number of additional observations.     

基于因子分析的汽车上市公司赢利能力评价

运用多元统计中的因子分析法建立赢利能力综合评价模型,并以汽车行业上市公司为研究对象,计算各汽车上市公司的行业内赢利能力得分,分析结果可为投资者投资、择股提供帮助,并为汽车上市公司的经营决策提供一定的决策依据.     

异步电机教学实验数据处理系统

本文介绍异步电机空载、短路、负载实验数据处理的数学方法和软件设计方法步骤,形成了实验教学软件。     

The effect of cell phones on international motor vehicle fatality rates: A panel-data analysis

This paper analyzes the effects of cell phone usage and economic freedom on motor vehicle death rates by estimating regression models on data for three years across 38 countries. The models incorporate a representative set of motor vehicle fatality determinants. Results indicate that cell phone use has a statistically significant nonlinear impact on highway death rates and that economic freedom does not appear to have an effect.     

国家标准《数值修约规则与极限数值的表示和判定》在车用汽油胶质含量测定中的应用

本文根据胶质含量测定试验方法的要求，以车用汽油中胶质含量（包括未洗胶质含量和溶剂洗胶质含量）测定为例，探讨了0．5单位数值修约、极限数值的表示和判定在胶质含量测定数据处理和结果判定中的应用。目的在于使车用汽油产品检测工作中在数据处理、报告和结果判定方面更加规范和统一。     

案例教学法在高职法律教学中的应用

案例教学法是高职法律教学中一种重要的方法,其对掌握法律理论知识、提高学生综合素能、调动学习积极性、强化教学效果都有帮助。运用案例教学法应遵从相应的步骤并注意若干问题,以发挥其在法律教学中的作用。